Sharing Taboo 3D Printer Files with Distortion Encryption

By Norman Chan

It's not illegal if it's just art.

While legislation, policy, and society struggle to figure out how to cope with new technology, there are some people who can't wait for government to decide how to deal with innovations like ride-sharing services and wearing tech. That's especially the case with 3D printing; 3D modelers who share their creations on sites like Thingiverse are receiving new scrutiny from copyright holders, and the government is keeping a close eye on firearms files like the ones created by Cody Wilson's Defense Distributed. Designer Matthew Plummer-Fernandez isn't taking sides with those issues, but was curious about 3D printer users' ability to share potentially taboo files in plain sight using encryption. He recently released Disarming Corruptor, a simple tool that takes a standard STL 3D printing file and distorts it using user-entered algorithm keys. Since 3D files are just an organization of vertices and mesh data--essentially a list of numbers--the tool can just as easily reverse the distortion effects if another user has the right decryption keys.

In that way, Disarming Corruptior is like any other encryption tool, but what makes it unique is that its output is just another STL file that can be read by a modelling program or 3D printed itself. The shape and intent of the original model can't be determined by opening the processed file, so it offers 3D modelers a level of privacy when distributing their work online. As Wired's profile on Plummer-Fernandez points out, the tool doesn't prevent law enforcement or governments from simply taking down any file suspected of being modified with Disarming Corruptor, but it's up to the 3D printing community to self-regulate and use it for the good of open design. Like the manufacturers of 3D printers and developers of modelling tools, Plummer-Fernandez is just providing the technology.